Telephone system



July 24, 192s.

L. L. EAGoN TLPHONE SYSTEM Filed Dec. 9, 1926 Patented July 24, 1928.

UNITED STATES PATENT, OFFICE,

LLOYD i.. EAGON, or 'New YORK, KN.- Y., AssiGNoit To AivrriiaicJANkTELEPHONE AND TELEGRAPH COMPANY, A CORPORATION or New YORKL TELEPHONESYSTEM.

Application filed Decelnb'er, 1926. Serial No. 153,72.

This invention relates to telephone systems and more particularly tomeans for testing all-trunks-busy registers and circuits therefor-in atrunking system.

lAccording to this invention a circuit arrangement is provided `wherebyaregister responsiveto the busy'rcond-iti'on'of a group of trunks, andlocated at the trunk terminating station, may be tested as to its`operation under the' all-trunks-busy condition', and

whereby the results-Of sucha test maybe in-` dicated at the trunkoriginating station.

The arrangement also makes it possible to ldetermine it the register,under the alltrunks-busy condition, isl'actuated dueto the combinedctt'ect produced by circuit-operation kot all ot' the busy trunks in thegroup; that is,tests may be made to ascertain if each individual trunkis actually involved, wheny busy, ,in yeffecting the operation ofy thereg-V ister.

The invention has rbeen illustrated in the accompanying drawing in whichVit has been applied to' a straightforward trunkingfsystem. 1

- yReferring to the draw-ing, l shows the callf ingend of an ordinarycord circuit, and 2,- 3

anda show straightforward trunk circuits in diagrammatic form whichI arerepresentative ot' a group of such trunks originating at i station Aand'terininating at station B. An all-trunks-busy*register 6 and itscircuit arrangement is associated with these trunks at4 tr'uiiks-busylregister 8 associated therewith;

An all-trunks-bus'y test jack 9 is'connected with registers' 6 and 8in'a circuit arranged in accordance with this invention. n

In testing register 6 and its circuits at station B by the operatoratstatio'n A, it'may* be agreed between the operators at these twostations that trunk 2 and cord l shall be used for transmitting andindicating the results of the tests yto the operator at A and that othercords shall be used in connection with the other ytrunks in the group totest the conditions of these trunks in regard to the control that theyhave over the operation of the register. It is assun'ied that'the testof the all-trunks-busy register 6 will. be

conducted when the traffic over this group of' trunks is light so as notto interfere with the regular use of the system.

The first Operation will be i'or the operator 'lighted lthrough thesleeve circuits. vcircuit orthefoperation of relayl7 may bev traced'from battery at the repeating coil 19 at A to insert plug l()r intojack ll of the trunk2 and for the operatorat B to insert plug l2 oftrunk'2 into the all-truiiks-busy test jack 9; The next operation willbe for the operator at A to insert the plugs of other lcords into jacksl5 and 1.6 ot'trunks 3 and/i and into the corresponding jacks of all ot'the `other' trunks of the group. When all Ot the trunks ot' this grouphave been made busy'in this manner, relays ysuch as 17 will be actuatedin all the trunks, and all the supervisory. lamps such as' 18 of all thecords connected to the trunks in vthis group will be lighted. Thesupervisorylamp` will Vbe The ot cord l., the supervisory relay 2l),ring terminals of plug l0 and jack ll, ring conductor ot' trunk 2, thelower lett-hand winding of repeating coil 21, the windings of relay 17inseries, upper lett-'hand winding of repeatingcoil 2l, tipV conductorot'y trunk 2 and tip terminals of jack ll 'and plug l0 to ground atrepeatino coil 19. The operation of relays,such as 1:7, of trunks 3 and4l land tlie=other trunks in the group 'causes' the operation ofrelays,such as 22, 23, 24 and the corresponding relays of 'the other trunks, tobeactiiatedi The'comp'lete circuit for the operation oi' rela`y22 due tothe Operation of relay 17 has not beenshown, but it has been indicatedthat the operation of relay 17 closes" L -connection 'to ground for acircuit that will beclosed' in ordinary straightforward'tr'unks to oneend ofthe winding of relay 22, the other end ont which is connected tobattery, ,whilethe circuits for the operation of relays and 24'havebeenentirely Omitted; For ya moreconiplete disclosure of straightforwardtrunk circuit operations reterence' maybe had tothe application, forypatent of Horace` W. Ulrich, Serial No. 156,- 570, ytiled Dec. 23,19262 It is evident from the drawing'thatv relays 22,23 and 24 and theother corresponding relays of the other tru'nksin the group in operatingopen thepcircuit tor relay 25 at their armatures and back contacts.'Hence, under these circumstances, rela'y25 will releasevand lclose anobvious circuit for the operation of register G. ltegister 6 now closesa circuit for the operation oi' the supervisory relay 28, from battery,righthand lower winding of repeating coil 2l,

18 to be lighted.

' supervisoryv the trunks in the group,

winding of supervisory relay 28, ring terminals ot plug 12 and jack 9,resistance 27, armature and front contact of register 6 to ground. Theoperation of relay`28 is possible due to the connection of a ground tothe tip terminals ot plug 12 and jack 9 through resistance 29 whichcauses the tripping of the usual ringing relay (not shown) in the trunkcircuit 2 which causes the circuit 'for relay 28 to be closed as is wellknown in the art. rlhe ringing circuit arrangement 'for trunk 2 has notbeen shown, as it forms no part ot this invention. The operation otrelay 28 short-circuits the high resistance right-hand winding of relay17. `his, as is well-known in the art, causes the operation oitsupervisory relay and the operation oi this relay causes the supervisorylamp 18 to be extinguished. The extinguishing of lamp 18 indicated tothe operator at A that the register 6 has operated as a result of thebusy condition ot all of the trunks in the group.

It it, however, is now desired to test whether or not the trunks, suchas 3 and l and .the other trunks inthe group, were actually involved incausing the operation ot register 6, the plugs inserted in the jacks otthese trunks at station A are removed and inserted in succession. At theremoval et any one of these plugs, it is evident that the correspondingrelay, such as 23 or 24, on releasing will cause relay 25 to be actuatedand thus release register 6. Register G in releasing permits thesupervisory lamp It' the lamp 18 does not light when a plug` is removedfrom one of it is evident that the circuits tor this trunk were notproperly involved inthe operation otregister 6 or that some other detectin the circuit was present.

It is evident that trunk 2 cannot be tested as to its part in theoperation of register 6 unless the plug 12 is removed vfrom jack. 9 andthe plug of another trunk in the groupA is inserted into jack 9. In thismanner trunk 2may be tested by removing and inserting plug 10 in jack11. The results of this test will then be indicated at the supervisorylamp of the cord connected to the trunk with which jack 9 is connected.

1n this manner, therefore, the operation ot register 6 at station B andthe proper functioning of the circuits individual to the trunks of thegroups tor causing the operation ot register G when all trunks are busy,may be tested and the results indicated at station A.

The test circuit, comprising jack 9 and the circuits connected theretoat the armatures and 'front contacts of registers 6 and 8, may be used'for testing the group oit trunks to which trunk 7 belongs and theoperation ot register 8 in a manner identical to the testing oi registerG. In this case plug 31 trunks originating at one of of trunk 7 may beinserted into jack 9 and the release ot relay 32 when all trunks in thisgroup are made busy will cause the operation ot' register 8. Y

It should beunderstood that the present disclosure is merelyillustrative ot one application oit the invention and that otherapplications to different system could readily7 be made. 1t is evidentthat othertest cir cuits such as the one connected to. jack 9 andregisters 6 and 8 may be provided for other groups ot trunks orthat anyVarrangement may be made to suit special require-` ments. For example,

of trunks may be too large to be handled by .means oi' a singletestcircuit and in this case a separate test jack may be providedv toreach group with the ring conductor-circuit controlled from thecorresponding register armature and front contact. f

`What is claimed is: Y ,Y 1. In a telephone system, two stations, vysaid stations and terminating at the other, the trunk terminatingstation, means at the trunk originating station for making all of saidtrunks busy, means at the trunk terminating station 'for actuating saidregister in response to the busy condition of all of said trunks, andmeans for indicating the actuation ot the register at the trunkoriginating station. y Y l y 2. ln. a telephone, system, two stations,trunks originating at one of said stations -and `terminating at theother, aV register at the trunk terminating station, means at the trunkoriginating station for making all of said trunks busy, means at thetrunk'terminating station for actuating said register in response to thebusy condition of all of said trunks, a signaling means at the trunkoriginating station, and means for actuating said signaling means inresponse to the actuation ot said register.

3. 1n a telephone system, two stations, a

group of trunks originating at one of said stations and terminating atthe other, a register at the trunk terminating station, cord circuits atthe trunk originating station, a signal associated with each of saidcord eircuits, means responsive to the connection of a cord circuit toeach trunk for actuating the corresponding signal, means responsive tothe connection ot cord circuits to all'the trunks in said group foractuating said register, and means responsive to the actuation et saidregister'tor disabling any .one of said signals.

4. ln a telephone system, two stations, trunks originating at one ofvsaid stations and terminating at the other, a register at the trunkterminating station, means at the trunk originating station 'forniakingallv of said trunks busy, means responsive to the busy condition of alloi' said trunks for ac# a register at the individual groups Y Sil izo

tuating said register, a circuit at the trunk terminating stationassociated With said register, means for connecting the terminating endof one of said trunks to' said circuit, and means responsive to saidconnection and to the actuation of said register for indicatin at theoriginating end of said connecte trunk the actuationof said register.

5. 1n a telephone system, tWo stations, a group of trunks originating atone of said stations and terminating at the other, a register at thetrunk 'terminating station, cord circuits at the trunk originatingstation, a signal associated With each of said cord circuits, meansresponsive to the connection of a oord circuit to a trunk for actuatingthe corresponding signal, means responsive to the connection of a cordcircuit to each trunk in said group for actuating said register, acircuit associated with said register, means for connecting said circuitWith the terminating end of' any one of said trunks, and meansresponsive to such a connection and to the actuation of the register fordisabling' the signal associated With the cord circuit connected to saidtrunk.

In testimony whereof, I have signed my name to this speciiication this8th day of December, 1926.

LLOYD L. EAGON.

